Display devices in which a cover glass is placed on a front surface of a display panel are known. As a result of providing the cover glass, the display panel can be protected, and design of display device can be improved.
Strength and safety of display devices have been improved by a cover glass being multi-layered (refer to JP 2010-008450 A, for example). When the cover glass is configured by a so-called laminated glass in which plates of glass are stacked, the strength of the cover glass improves. Also, with such a laminated glass, even when the glass is broken or clacked, scattering of pieces of broken glass can be suppressed by an adhesive that bonds the glass, and as a result safety is improved.
In the cover glass including layers, like the laminated glass on the market, films that express adhesiveness due to heat can be used as a middle film for bonding glass. In films that express adhesiveness due to heat, a film whose transmittance of ultraviolet light is reduced has been commonly used. This is because this type of thermal adhesive film is used in building applications and automotive applications, and it is preferable that the ultraviolet light is not transmitted therethrough. The ultraviolet light cutting off function is often realized by an ultraviolet absorbent being contained in the thermal adhesive film. This type of thermal adhesive film is designed such that the optical transmittance at a wavelength of 365 nm is decreased as much as possible, using the wavelength of 365 nm as a reference.
However, in order to suppress a double reflection of an image, resin can fill a space between the cover glass and the display panel. This resin can be formed of a photo-curable resin. In this case, when the above thermal adhesive film is used for bonding the cover glass, there is concern that the thermal adhesive film cuts out light of a wavelength with which the photo-curable resin is cured, and the photo-curable resin is not favorably cured.